Steam-engine valve-gear.



W. S. BROWN.

STEAM ENGINE VALVE GEAR.

APPLlCATlON FILED JULY 12. 1915.

Patented Mar. 26,1918.

2 SHEETS-SHEET 1- awvmtoz W. S. BROWN.

STEAM ENGINE VALVE GEAR. APPLICATION FILED JULY 12. 1915.

Patented Mar. 26, 1918.

2 SHEETS-SHEET 2.

Tl STAT WILLIAM SHERMAN BRIQ'WN',

" 3F KNOXVILLE, TENNESSEE.

STEAM-ENGINE VALVE-GEAR.

Specification of Letters Patent.

Patented Mar. 26, 1918.

Application filed July 12, 19-15. Serial No. 39,330.

To all whom it may concern:

Be it known that I, IVILLIAM SHERMAN BROWN, a citizen of the United States, residing at Knoxville, in the county of Knox and State of Tennessee, have invented anew and useful Improvement in Steam-Engine Valve-Gear, of which the following is a specification, reference being had to the accompanying drawing.

My improvement relates particularly to mechanism for transmitting motion from the drive wheel or axle of a steam locomotive to the distributing valve which admits steam to the cylinder.

The object of the improvement is to provide a construction which is simple, has the parts aecessibly located, and which avoids irregularity of valve action due to lost motion or pounding at the crank.

This improvement is analogous to the mechanism described by my United States Patent No. 1,033,532, granted July 23, 1912, for steam engine valve gear, (reissued July 11, 191 1, No. 13,770), and by my United States Patent No. 1,100,668, granted June 16, 191%, for steam engine valve gear.

In the accompanying drawings,

Figure 1 i a side elevation, portions being broken away, showing my improvement applied to one side of a locomotive;

Fig. 2 is a plan of a portion of the mecha nism shown by Fig. 1;

Fig. 3 is a section on the line, 33, of Fig. 2, looking toward the right;

Fi 4 is a section on the line, 44, of Fig. 2, looking in the direction of the arrow;

Fig. 5 is a plan of the bridge which forms a support for portions of the mechanism;

Fig. 6 is a side elevation of said bridge;

Fig. 7 is a section on the line, 77, of Fig. 1, looking toward the left;

Fig. 8 is a horizontal section on the line, 88, of Fig. 1;

Fig. 9 is a section on the line, Fig. 1.

Referring to said drawings, 1 is the usual valve stem extending to the distributing valve (not shown). The usual horizontal, parallel cross-head guide bars, 2, are supported at their rear ends by the guide yoke extension, 3. The usual connecting rod or pitman, 1, is coupled to the usual main crank, 5, carried by a drive wheel, D. 'On the main crank, 5, is rigidly mounted an auxiliary crank, 6, standing 90 degrees forward of the main crank. To said auxiliary crank is coupled one end of the auxiliary pitman rod, 7.

A bridge, B, i located above the frame, A, and extends from the ordinary guide yoke, 8, and the guide yoke extension, 3-, to the cross beam or plate, 10, and is secured to said guide-yoke and to said cross-beam by means of bolts, 9. Said bridge is in the form of a plate havingits length horizontal and being turned to bring itslong edges into an upright plane. At its rear end, the bridge has a lateral extension, 11, resting against the cross beam, 10, and receiving said bolts, 9. At its forward end the bridge has a transverse extension, 12, reaching to both sides of the body of the bridge and resting against the guide yoke extension, 3, and receiving said bolts, 9. Said bolts extend throu 'h the transverse extension, 12, and the guide yoke, 8, whereby the forward end of the bridge is firmly secured to the guide yoke, and the guide yoke extension, the bridge being left clear between its ends. On the outer portion of the transverse extension, 12, and integral therewith is an car, 13, whi h is directed rearward; and on the inner portion of aid transverse extension is another car, 14, also directed rearward and located horizontally opposite the car, 13. Each of said cars has a bearing, 15, receiving the ends of a shaft, 1 On said shaft is a bell crank or rocking member, C, preferably rotatable on said shaft, the latter being held immovably in its bearings. Said bell crank has two approximately horizontal arms, 17 and a depending arm, 18. The lat ter arm is coupled to the valve-stem. 1. By rocking the bell-crank, the valve-stem is re ciprocated endwise.

An approximately upright link, 19, has its upper end coupled to the arms, 17, of the bell crank, while its lower end is coupled to the forward end of the auxiliary pitman rod, 7, by a bolt, 20, both ends of said link being forked to receive said rod and said arms, as shown in the drawings. Said arms, 17, are also forked to receive the upper ends of the link, 19.

In the bridge, 13, is a horizontal slot, 21. In said slot, is a slide block, E, by which is supported the lower end of a rocking member. F. Said member comprises two parallel plates, 22, placed at opposite sides of the slide block and the bridge. A bolt, 23, extends through the lower ent. of said plates and the slide block. Each plate, 22, has at its upper end a horizontal bearing, 24:, extendin toward the other of said plates and resting against the bearing, 24, of the other of said plates. On each of said bearin s is an upright extension, 25. A horizontal olt, 26, extends transverselythrough said extensi'onsand binds them together. A sleeve, 27, extends loosely through the bearings, 24, and is long enough to project slightly out of sald bearings. A bolt, 28, extends through said sleeve. I

A link, 29, which is forked at each end, has its upper arms extending to opposite sides ofthe bridge and the rocking member, F. At the upper end of each arm of said link is a bearing, 30, which is extended-toward the other of said bearings and against the end of the sleeve, 27, so that a space is left between each of said arms and the adjacent plate, 22. The bolt, 28, also extends through said bearings. v

The forkat the lower end of the link, 29, extends to opposite sides of the auxihary piston rod, 7. A bolt, 32, extends honzontally through said fork andthe auxillary rod, 7, said bolt being so placed on said rod as to be in substantially upright alinement with the axis of the slide block when the latter is in its middle position and the aux iliary crank is on its upper or lower quarter.

The forward end of the auxiliary reach rod, 33, is forked and extends to opposite sides of the upper end of the link, 29, and the bolt, 28, extends through the arms of the auxiliary reach red as well as through the link, 29, and the bearings, 24, of the rocking member, F.

The rear end of said auxiliary reachrod is coupled to the upright rocking arm, 35, which is rigid on the reversing shaft, 36, supported in bearings, 37. On said reversingshaft is an arm, 38, to which is coupled a reach rod, 39, which is in turn coupled to the ordinary reversing lever, 40, working on a sector or quadrant,-41. A sub-aux iliary reach rod, 42, forked at each end, has its forward end extending to each side of the lower portion of the rocking member, F.

' The bolt, 23, which extends through the rocking member and the slide block, also extends through the adjacent portions of The rear end of said sub-auxiliary'rea'ch rod extends to opposite sides of the upright rocking arm, 35, which, as above stated, is rigid on the reversing shaft, 36; and a bolt, 43, extends horizontally through said rod and said upright arm.

When the auxiliary reach rod, 33, is moved endwise the tilting of the arm, 35, in response to endwise movement. ofthe reach rod, 39, the sub-auxiliary reach rod is moved in the same direction, but not so far. Such movement of thesub-auxiliary reach rod causes a corresponding sliding of is on the upper or the lower quarter.

the slide block, E, and the bolt, 23. The axis of said bolt constiutes an axis of oscillation for the rocking ine1nber,"F. Hence the curve through which the axis of the bolt, 28, is carried by the rocking of the member, F, does not have for its axis the axis of the bolt, 23. On the contrary, the said curve is approximately on'a radius eentering on the axis of the bolt, 32, when the latter is in its middle position and the auxiliary (llitllilk T e curve actually described by the axis of the bolt, 28, is the result of a compound movement, to wit: the tilting of the member F, on the axis of the bolt, 23, and the bodily sidewise movement or shifting of the bolt and the rocking member, the several parts concerned in the production of this compound movement being so proportioned and related to each other as to give said curve an axis which coincides approximately with the axis of the bolt, 32, when, as above stated, the auxiliary crank, 6, is on the upper quarter or on the lower quarter.

During the rotation of the driver, D, the auxiliary rod, 7 is reciprocated endwise, its forward part being supported by the link, 29, which at this time oscillates on the axis of the bolt, 28., at the upper end of the rocking member, F. Said axis takes various positions in the larger curve already described, according to the position into which the auxiliary reach rod, 33, and the rocker arm, 35, are set. The valve gear is on center, when the axes of the bolts, 28, 23, and 32, are in the same upright plane, at which time the auxiliary crank is on the upper or lower quarter.

During each reciprocation, said auxiliary pitman rod rocks bodily with the axi of the bolt, 32, as a fulcrum. This involves the rising and falling of the forward end of said auxiliary rod, and during such movement of said end of said rod, the link, 19, is forced up and down, and such movement of said link cause the rocking of the bell crank, C, and the reciprocation of the valve stem, 1. 7 V I The gear is reversed by throwing the reversing lever across the center in, the usual manner, and the opening of the valve is varied by moving the upper end of the link,

29, nearer to or farther from the center.

approximately equals the length of the link,

29, although the rocking member is much shorter than the link, 29. If the axis of the rocking member were not thus made shiftable, said rocking member would have to be approximately as long as the link, 29, as is the case in the gear described in my above mentioned Patent No. 1,100,668, that gear having a hanger extending down from the bridge low enough to support the axis of the rocking member in approximate ali-nement with the axis of the link which corresponds to the link, 29, of the gear of this application.

By thus shortening the rocking member, several advantages are obtained, among which may be mentioned the omission of the hanger, whereby greater stability is obtained. Furthermore, the rocking member may be placed within the fork of the link,

29, whereby the parts are balanced by being supported symmetrically on an upright plane cutting the bridge lengthwise. This affords greater stability and durability, diagonal strains on the rocking member, the link, and the bridge, being avoided.

It is to be observed that the reversing mechanism acts differentially on the rocking member, different portions of the rocking member being carried through different distances. Hence, we have in this combination of elements a differential reversing mechanism. This differential characteristic comes through the rocker arm, 35, the auxiliary reach rod, 33, and the sub-auxiliary reach rod, 42, the rocker arm imparting to said reach rods different ranges of movement, and said rods imparting different movements to the upper and lower portions of the rocking member.

I claim as my invention,

1. In a valve gear, the combination of a frame, a distributing valve stem, a rocking member, means in operative relation with said member at two elevations for rocking and bodily reciprocating it sidewise and securing it at any stage of its movement, an auxiliary rod, means for actuating said rod, means opera-tively relating said rod to said rocking member, and means for connecting said rod and the stem of the distributing valve, substantially as described.

2. In a valve gear, the combination-of a frame, a distributing valve stem, a rocking member, means in operative relation with said member at two elevations for rocking and bodily reciprocating it sidewise and securing it at any stage of its movement. an auxiliary rod, means for actuating said rod, a link operatively relating said rod to said rocking member, and means for connecting said rod and the stem of the distributing valve, substantially as described.

3. In a valve gear, the combination of a frame, a distributing valve stem, a rocking member, means in operative relation with said member at two ele ations for simultaneously rocking and bodily reciprocating it sidewise and securing it at any stage of its movement, an auxiliary rod, means for actuating said rod, means operatively relating said rod to said rocking member, and means for connecting said rod and the stem of the distributing valve, substantially as described.

is. In a valve gear, the combination of a frame, a distributing valve stem, a rocking member, means in operative relation with said member for simultaneously rocking and bodily reciprocating it sidewise and securing it at any stage of its movement, an auxiliary rod, means for actuating saidrod, a link operatively relating said rod to said rocking member. and means for connecting said rod and the stem of the distributing valve, substantially as described.

5. In a valve gear, the combination of a frame, a distributing valve stem, a rocking member, means in operative relation with said member fonrockinp; and bodily reciprocating it sidewisc and securing it at any stage of its movement, an auxiliary rod, means for actuating said rod, a link operatively relating said rod and said rocking member, and means comprising a bell-crank for connecting said rod and the distributing valve, substantially as described.

- 6. In a steam engine valve gear, the combination of a distributing valve stem, a rocking member. a support upon which said rocking member is bodily shiftable sidewise, reversing mechanism in operative relation with the upper portion and the lower por tion of said rocking member to reciprocate said member bodily sidewise, the upper portion being moved faster and farther than the lower portion during each reciprocation, and securing said rocking member in any stage of its movement, an auxiliary crank, an auxiliary rod having one end coupled to said crank, an approximately upright link coupled to said auxiliary rod and to the upper portion of said rocking member, and means for connecting said auxiliary rod into operative relation with the stem of the distributing valve, substantially as described.

7. In a steam engine valve gear, the com bination of a distributing valve stem, a rocking member, a support upon which said rocking member is bodily shiftable sidewise, reversing mechanism in operative relation with the upper portion and the lower portion of said rocking member to reciprocate said member bodily sidewise, the upper portion being moved faster and farther than the lower portion during each reciprocation, and securing said rocking member in any stage of its movement, an auxiliary crank, an auxiliary rod having one end coupled to said crank, an approximately upright link coupled to said auxiliary rod and to the forward portion of said rocking member, and means comprising a bell-crank for connecting said auxiliary rod into operative relation with the stem of the distributing valve, substantially as described.

8. In a steam engine valve gear, the combination of a distributing valve stem, a

bridge, a rocking member slidably supported by said bridge, a reversing lever in operative relation with said rocking member at two elevations, for rocking and bodily shifting said member along said bridge, an auxiliary crank, an auxiliary rod having one end coupled to said crank, an approximately upright link coupled to said auxiliary rod and having its upper end coupled to the free portion of said rocking member, and means connecting said auxiliary rod into operative relation with the stem of the distributing valve, substantially as described.

9. In a steam engine valve gear, the combination of a distributing valve stem, a

rocking member, a slidable support for said rocking member, a reversing member in operative relation with the said slidable support for reciprocating said support sidewise, another reversing member in operative relation with the upper portion of said rocking member for reciprocating said portion of said member bodily sidewise farther than the lower portion of the rocking memher is reciprocated, means for securlng' said reversing members in any stage of their movements, an auxiliary rod, means for actuating said rod, an approximately upright link coupledto'said auxiliary rod and to the upper portion of said. rocking memher, and means for connecting said auxiliary rod into operative relation with the stem of the distributing valve, substantially as described.

10. In a steam engine valve gear, the combination of a distributing valve stem, a rocking member, a slidable support for said rocking member, a rocking arm, a reversing member connected to said rocking arm and to the slidable support, another reversing 11. In a steam engine valve gear, the com 7 bination of a distributing valve stem, a

'bridge, a rocking member extending to opposite sides of and slidably supported upon said bridge, a forked link extending upward along opposite sides of said bridge and said rocking member andbeing coupled to the upper part of said rocking member, reversing mechanism in operative relation with said rocking member at two elevations for bodily reciprocating said member sidewise, the upper portion being given a longer path than the lower portion, means for securing the reversing mechanism in different positions, an auxiliary rod coupled to the lower end of said link, means for actuating said auxiliary rod, and means for operatively connecting said rod with the stem of the distributing valve, substantially as described.

12. In a valve gear, the combination of a frame, a distributing valve stem, a rocking member, differential reversing mechanism engaging the rocking member for reciprocating it sidewise and securing it at any stage of its movement, an auxiliary rod, means for actuating said rod, means operatively relating said rod to said rocking member, and means connecting said rod and the stem of the distributing valve, sub stantially as described.

In testimony whereof I have signed my name, in presence of two witnesses, this 29th day of June, in the year one thousand nine hundred and fifteen.

WILLIAM SHERMAN BROWN.

copies of this patent may be obtained for five cents each, by addressing the Commissioner of Yatents,

Washington, I). G. 

